How does one?force? decrease in pollution without imposing unacceptable governmental controls on the population? In the U.S., many have believed that the free market, with applicable oversight, can accomplish this. For example, in the late 1800s, the main provider of transportation (at least for short distances) was the horse. At 15 to 35 pounds of manure a day, pollution in cities was a significant problem. In addition, the piles of manure served as breeding grounds for insect life...